1. Technical Field
The present invention relates to a theft prevention device and a theft prevention method for a vehicle, in particular to a theft prevention device and a theft prevention method which prevent a vehicle from being stolen by performing authentication before starting the vehicle.
2. Related Art
In recent years, many vehicle thefts occur, so that movement to employ legal regulations related to a vehicle theft prevention system rises. In Canada, 5-minute attack test performance criterion is proposed and it is required that an engine does not start even if a vehicle theft prevention system is attacked for five minutes.
As a vehicle theft method, there is a method of replacing all related devices such as an immobilizer that performs authentication related to theft prevention. In order to prevent theft even in this method, a technique that significantly limits functions of a vehicle is disclosed (see Japanese Patent No. 3832347).